The objective of this study is to assess whether modafinil treatment promotes abstinence and reduces high risk sexual behavior associated with HIV seroconversion (HRSB) in women who are addicted to cocaine. Preventing the heterosexual transmission of AIDS is arguably the greatest challenge that currently confronts the medical community. Women addicted to cocaine are at great risk of HIV seroconversion when they engage in HRSB (e.g., trading sex for cocaine, having unprotected sex with multiple partners) to obtain cocaine, which is readily available within urban communities. An effective means of identifying and treating these women should reduce HRSB that jeopardizes them, their sexual partners, and their partners' partners. This project will utilize a mobile outreach van (MOV) that places our research team in the center of West Philadelphia neighborhoods where cocaine is heavily trafficked and consumed, allowing us to identify women in urgent need of education and addiction treatment. After informed consent and a comprehensive medical/psychiatric screening, qualifying subjects will receive HIV testing with pre-test and post-test counseling designed to provide effective education regarding HIV transmission. Subjects will then be randomized to modafinil (300 mg/day) or placebo treatment for a period of 8 weeks with study medications dispensed and monitored in the MOV to optimize subject convenience and medication adherence. Modafinil is a promising agent that blocks cocaine-induced euphoria under controlled conditions, and was recently reported to promote cocaine abstinence in a controlled pilot study. Psychosocial treatment will involve Telephone Monitoring and Adaptive Counseling (TMAC), an innovative and cost-effective approach that provides a feasible means of treatment delivery to the target population. Cocaine abstinence will be measured objectively with twice weekly urine testing and HRSB will be measured with the Risk Assessment Battery (RAB). Follow-up assessments will be scheduled 3 and 6 months after randomization to further assess cocaine abstinence and HRSB. Subjects will be genotyped to assess genetic vulnerability to cocaine dependence and pharmacogenetic factors associated with their response to modafinil. Thus, this project employs innovative means of identifying, treating, and characterizing a target population in need of effective treatment designed to promote recovery and prevent HRSB.